A sea thermal power plant of the type to which the present invention relates is disclosed in an article entitled "Power from the Sun by Way of the Sea", published in "Power+for January and February of 1965. Briefly, the generating system disclosed includes a turbine driven generator and the boilder for the turbine is heated by warm ocean surface water and the turbine exhaust is condensed in a heat exchanger cooled by cold ocean water obtained by pumps driven from the system to elevate such water from substantial depths. It is necessary to start at least the cold water supply pumps to cause a sufficient pressure difference between vapor in the boiler and vapor in the condenser to cause flow of working fluid through the turbine to generate power.